Data recovery from an inaccessible G-RAID 8TB Thunderbolt drive showing a red light on power-up

Data recovery from an inaccessible G-RAID 8TB Thunderbolt drive showing a red light on power-up Data Recovery Ireland
The 8TB G-Drive Thunderbolt from G-Techology with HGST 4TB S-ATA Disk X 2 which was unfortunately configured in RAID 0.

DAS (or direct access storage) devices are ideal for tasks involving high data throughput such as photo or 4K video editing. Unlike an NAS, no network equipment such as routers or switches are required. The device can simply be attached to a host system using a USB or Thunderbolt connection.

To increase the I/O (input / output) rates of these devices, it is common for manufacturers to use a RAID 0 configuration. This simply means that two (usually S-ATA HDDs) disks are joined at the hip (using software) to form one (NTFS, HFS+, EXT3 etc.,) data volume. If large files need to be transferred to the volume, the data is written concurrently to the two disks (instead of just one) making the write operation faster.  For example,  typical write speeds would be around 320 MB/s. This is a relatively fast speed for spinning metal platters and is a perfect example of how storage devices can exploit data parallelism afforded by RAID.  

However, there is a downside to using RAID’ed disks like this. Namely if one disk fails, the whole volume topples over like a proverbial house of cards. And this is exactly what happened to a customer we were helping last week. Their 8TB G-RAID (12V 5Amp) device had two HGST 4TB S-ATA disks (HUS726040ALE614) in a RAID 0 configuration. One of the HGST disks developed firmware issues and bad sectors causing the volume to become unrecognised by Windows. When our customer connected his G-RAID drive to his Windows 10 system, it was no longer showing up. Instead, they got an ominous red light on power up.  

Reasons why your G-Technology G-RAID drive no longer shows up in Windows or Mac.

  • One or more of the disks inside your G-RAID drive might have developed physical faults such as issues with the read-write heads. For example, heads can physically deform due to shock damage while some heads will just fail due to wear-and-tear. Problems with the read-write heads can make the MBR (master boot record), the firmware on the servo-tracks and the user-created data of each disk unreadable.
  • One or more of the disks inside your drive might have developed firmware faults. Firmware is microcode used by hard disks to manage the drive. It is typically stored on the ROM chip of the PCB and on the servo tracks of the disk. Firmware code helps manage errors on the disk and is also involved in crucial functions such as logical block addressing.
  • Another reason why your G-RAID rive is no longer being detected is that one or more of your disks inside your 4TB or 8TB G-RAID drive might have developed bad sectors. Sectors are the smallest area in a hard drive where data is stored. Some bad sectors are normal. In fact, most electro-mechanical hard disks leave the factory with some bad sectors already in place (this is recorded in the P-List). As the disks gets used, more bad sectors start to develop – these are recorded on the G-List. Then, after a while, a surfeit of bad sectors may culminate in your G-RAID drive failing to initialise.
  • The PCB (printed circuit board) inside your G-Technology G-RAID drive might have failed. This can occur due to thermal stress, over-voltage (e.g. a power surge) or due to liquid damage.  

Data recovery from a G-RAID device

Thankfully most of the problems with G-RAID drives can be fixed. In this particular case, we resolved the issues with the firmware and bad sectors. The using byte-for-byte disk images, we performed a detailed analysis on them ascertaining key RAID parameters that were used such as disk order, block size, block order and disk offsets. All of these are parameters are needed for the RAID rebuild process. We eventually rebuilt the RAID. We now had a complete NTFS volume and were able to recover all the drive’s data (video footage and .tiff images) for our very pleased customer.

Is your G-RAID drive not mounting on your Mac? Is your G-RAID drive not showing in Windows? Is your G-RAID disk freezing? Is your iMac or MacBook reporting that your G-RAID disk is “not readable”. Is your G-RAID drive showing a red light? Drive Rescue offer a complete data recovery service for G-RAID devices such as G-RAID Thunderbolt 4TB, 8TB and 12TB. We have extensive experience in recovering and repairing the hard disks (usually HGST 3.5” S-ATA) used inside these drives.